Photocatalytic Oxidative Cleavage of Alkenes by Molecular Oxygen: Reaction Scope, Mechanistic Insights, and Flow Application

Abstract

The oxidative cleavage of C�C bonds with molecular oxygen was promoted effectively by a catalytic amount of a decatungstate photocatalyst using black light irradiation (365 nm). Not only aromatic ketones but also aliphatic ketones were obtained by the photocatalytic protocol. The continuous flow reaction of α-methylstyrene using a highpower ultraviolet light-emitting diode (365 nm) dramatically decreased the reaction time.

Toward a Sustainable Photocatalytic Oxidative Cleavage of Olefins Mediated by Nitrate Radicals: The Influence of the Physicochemical Features of the Photocatalyst

“…Liu et al used visible light excited Bi 4 O 5 Br 2 to oxidize the olefin to the corresponding carbocation radical, which in turn undergoes [2 + 2] cycloaddition with the superoxide radical, giving a dioxetane intermediate, eventually evolving into the carbonyl compound. Similar mechanism has been reported by Shih et al in the presence of a decatungstate photocatalyst under UV light irradiation. Notably, only in the latter case could both aliphatic and aromatic ketones be obtained, while in all of the previous reports, the reaction takes place only in the presence of aryl substituted CC double bonds.…”

Photo‐induced Multiphasic Reactions in Flow Process: A Decade of Progress

“…In 2023, Rye and colleagues reported a photocatalytic oxidative cleavage of alkenes using oxygen gas as the oxidant to synthesize carbonyl compounds in both batch and flow systems (Scheme 7, top). [28] The use of a decatungstate photocatalyst under black light (365 nm) proved highly effective, yielding both aromatic and aliphatic ketones. When a highpower ultraviolet light-emitting diode (365 nm) was employed in a continuous flow reaction with α-methylstyrene 14, the reaction time was significantly reduced from 12 hours to just 6 minutes compared to the batch reaction.…”

“…In 2023, Rye and colleagues reported a photocatalytic oxidative cleavage of alkenes using oxygen gas as the oxidant to synthesize carbonyl compounds in both batch and flow systems (Scheme 7, top) [28] . The use of a decatungstate photocatalyst under black light (365 nm) proved highly effective, yielding both aromatic and aliphatic ketones.…”

Recent Advances in Photoinduced Oxidative Cleavage of Alkenes

“…A complimentary protocol to Xie's method was reported by Ryu and co-workers in 2023 employing TBADT catalyst with acetonitrile and water mixture, promoted by black/UV 365 nm light. 34 The authors showcased a slight expansion of scope toward aliphatic substrates. Using a continuous photoflow setup, the standard reaction time of 12-20 h in batch was significantly reduced to 6 minutes.…”